1. Field of the Invention
The present invention relates to an engine for a vehicle having a saddle, mounted on the vehicle in such a manner that an oil hydraulic automatic transmission for changing over the change gear ratio by control an oil pressure is incorporated in an engine body.
In addition, the present invention relates to a power transmission device for the vehicle, wherein a gear speed change mechanism included of a plurality of speed-stage gear train capable of being alternatively established between main shafts and a counter shaft, which extend in parallel to the vehicle width direction, is incorporated in an engine body mounted on the vehicle, and a drive bevel gear interlockedly connected to the counter shaft and a driven bevel gear fixed to a front and rear wheel drive shaft disposed in the vicinity of the center of the engine body along the vehicle width direction and extending in the front-rear direction of the vehicle are meshed with each other in the engine body.
2. Description of Background Art
A configuration in which an engine having an oil hydraulic automatic transmission is mounted on a vehicle having a saddle, and an oil pressure control unit having a plurality of control valves for controlling the oil pressure in the oil hydraulic automatic transmission, the control valves being stacked in a plurality of layers, is mounted onto a side surface of a crankcase of the engine has been known. For example, see Japanese Patent Laid-open No. 2003-90260.
However, in the configuration in which the oil pressure control unit is mounted on a side surface of the crankcase as disclosed in Japanese Patent Laid-open No. 2003-90260, there is a need for a measure for protecting the oil pressure control unit against scattered matters which may be scattered from the ground surface attendant on the running of the saddle ride type vehicle.
In addition, a power transmission device for a vehicle wherein a counter shaft in a gear speed change mechanism is disposed on the rear side of a crankshaft of an engine mounted on a saddle ride type vehicle and wherein a drive bevel gear fixed to the counter shaft and a driven bevel gear fixed to a front and rear wheel drive shaft are meshed with each other on the front side relative to the axis of the drive bevel gear, has been known. See for example, Japanese Patent Laid-open No. Sho 60-179337.
However, the driven bevel gear is large in diameter, in a configuration in which the drive bevel gear and the driven bevel gear are meshed with each other on the front side relative to the axis of the drive bevel gear as in the configuration disclosed in Japanese Patent Laid-open No. Sho 60-179337. Therefore, in order to prevent the driven bevel gear from interfering with speed change gears in the gear speed change mechanism, it is necessary to secure a sufficient vacant space, to obviate the arrangement of speed change gears in the area corresponding to the driven bevel gear, and/or to arrange a speed change gear with a sufficiently small diameter in the area corresponding to the driven bevel gear. As a result, the degree of freedom in laying out the speed change gears is reduced, and the engine body would be enlarged in size.